A dubbing loop is something every fly tier should learn how to use. You can form dubbing loops with a variety of fly tying materials. It locks in coarse dubbing that you may use on steelhead flies or salmon flies. Try inserting rabbit fur into a dubbing loop to create great leech flies or to form the abdomen on trout nymphs and stonefly nymphs. It also works great on synthetic materials like Angel Hair to form flashy bodies on smallmouth bass flies.